Expression of serum microRNA-155 and its clinical importance in patients with heart failure after myocardial infarction

Objective This study was conducted to investigate the level of microRNA-155 (miRNA-155) in patients with heart failure (HF) after myocardial infarction (MI) and its clinical importance. Methods Serum miRNA-155 levels were measured using quantitative reverse transcription (qRT)-PCR. The left ventricular ejection fraction (LVEF), left ventricular posterior wall thickness, and left ventricular end-diastolic diameter were measured by echocardiography. Serum amino-terminal pro-B-type natriuretic peptide (NT-proBNP) and other parameters were also analyzed. Results miRNA-155 levels in patients with HF were significantly higher than in control and MI groups. The area under the receiver operating characteristic curve of serum miRNA-155 in the diagnosis of HF after MI was 0.941, the cutoff value was 1.77, sensitivity was 92.73%, and specificity was 92.14%. NT-proBNP levels were significantly higher and LVEF was lower in patients with high versus low miRNA-155 expression. Conclusions Patients with HF after MI had elevated miRNA-155 levels and poor cardiac function, suggesting that determining miRNA-155 expression could be used to assess the severity of the disease.